Focused Ion Beam fabrication of superconducting scanning Probes

ended

Our vision is to enable a new era in scanning probe microscopy (SPM), in which nanometer-scale sensing devices – specifically superconducting devices – can be directly patterned on-tip and used to reveal new types of contrast. To realize this vision, we will use focused ion beam (FIB) techniques to produce sensors with unprecedented size, functionality, and sensitivity directly on the tips of custom-designed cantilevers. The key to this undertaking will be the unique capability of FIB to mill, grow, or structurally modify materials – especially superconductors – at the nanometer-scale and on non-planar surfaces. Our FIB-fabricated probes will include on-tip nanometer-scale Josephson junctions (JJs) and superconducting quantum interference devices (SQUIDs) for mapping magnetic fields, magnetic susceptibility, electric currents, and dissipation. Crucially, the custom-built cantilevers, on which the sensors will be patterned, will enable nanometer-scale distance control, endowing our probes with exquisite spatial resolution and simultaneous topographic contrast. The resulting imaging techniques will significantly surpass state-of-the-art SPM and help us to unravel poorly understood condensed matter phenomena, which are impossible to address with today’s technology.